[PATCH 22/34] iio: inkern: only return error codes in iio_channel_get_*() APIs
Nuno Sá
nuno.sa at analog.com
Fri Jun 10 01:45:33 PDT 2022
APIs like of_iio_channel_get_by_name() and of_iio_channel_get_all() were
returning a mix of NULL and error pointers being NULL the way to
"notify" that we should do a "system" lookup for channels. This make
it very confusing and prone to errors as commit dbbccf7c20bf
("iio: inkern: fix return value in devm_of_iio_channel_get_by_name()")
proves. On top of this, patterns like 'if (channel != NULL) return channel'
were being used where channel could actually be an error code which
makes the code hard to read.
Signed-off-by: Nuno Sá <nuno.sa at analog.com>
---
drivers/iio/inkern.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 87fd2a0d44f2..31d9c122199a 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -214,7 +214,7 @@ static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
const char *name)
{
- struct iio_channel *chan = NULL;
+ struct iio_channel *chan;
/* Walk up the tree of devices looking for a matching iio channel */
while (np) {
@@ -231,11 +231,11 @@ struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
name);
chan = of_iio_channel_get(np, index);
if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
- break;
- else if (name && index >= 0) {
+ return chan;
+ if (name && index >= 0) {
pr_err("ERROR: could not get IIO channel %pOF:%s(%i)\n",
np, name ? name : "", index);
- return NULL;
+ return chan;
}
/*
@@ -245,10 +245,10 @@ struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
*/
np = np->parent;
if (np && !of_get_property(np, "io-channel-ranges", NULL))
- return NULL;
+ return chan;
}
- return chan;
+ return ERR_PTR(-ENODEV);
}
EXPORT_SYMBOL_GPL(of_iio_channel_get_by_name);
@@ -267,8 +267,8 @@ static struct iio_channel *of_iio_channel_get_all(struct device *dev)
break;
} while (++nummaps);
- if (nummaps == 0) /* no error, return NULL to search map table */
- return NULL;
+ if (nummaps == 0) /* return -ENODEV to search map table */
+ return ERR_PTR(-ENODEV);
/* NULL terminated array to save passing size */
chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
@@ -295,7 +295,7 @@ static struct iio_channel *of_iio_channel_get_all(struct device *dev)
static inline struct iio_channel *of_iio_channel_get_all(struct device *dev)
{
- return NULL;
+ return ERR_PTR(-ENODEV);
}
#endif /* CONFIG_OF */
@@ -362,7 +362,7 @@ struct iio_channel *iio_channel_get(struct device *dev,
if (dev) {
channel = of_iio_channel_get_by_name(dev->of_node,
channel_name);
- if (channel != NULL)
+ if (!IS_ERR(channel) || PTR_ERR(channel) == -EPROBE_DEFER)
return channel;
}
@@ -412,8 +412,6 @@ struct iio_channel *devm_of_iio_channel_get_by_name(struct device *dev,
channel = of_iio_channel_get_by_name(np, channel_name);
if (IS_ERR(channel))
return channel;
- if (!channel)
- return ERR_PTR(-ENODEV);
ret = devm_add_action_or_reset(dev, devm_iio_channel_free, channel);
if (ret)
@@ -436,7 +434,7 @@ struct iio_channel *iio_channel_get_all(struct device *dev)
return ERR_PTR(-EINVAL);
chans = of_iio_channel_get_all(dev);
- if (chans)
+ if (!IS_ERR(chans) || PTR_ERR(chans) == -EPROBE_DEFER)
return chans;
name = dev_name(dev);
--
2.36.1
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